Piston



Jan. 13, 1931. DOCK 1,788,566

PISTON Filed Dec. 26, 1929 INVENTOR fler a)? 027 Z6 Z7 Z6 ATTORNEYPatented Jan. 13, 1931 UNITED STATES PATENT HERMAN DOCK, OFGUADALAJ'ARA, MEXICO OFFICE PISTON Application filed December 26, 1929.Serial No. 416,898.

- My invention relates to pistons, and especially to a new and improvedpiston, rod and bearing construction or arrangement which replaces thepin-and-sleeve bearing commonly usedin trunk or other pistons, andeliminates the various disadvantages of such wrist bearings, asunderstood by skilled persons.

The invention consists in an improved and simplified part-sphericalbearing connecting a piston and rod or pitman, providing in comparisonwith the ordinary wrist pin bearing, greatly increased bearing surface,greater strength and practical immunity from breakage, automaticaccommodation to slight misalignment of piston, or cylinder andcrankshaft, improved facility for lubrication, aud various otheradvantages sufliciently referred to hereafter.

Particularly, the invention provides an improved and simplifiedlowerpiston bear-' ing (or a rod-bearing. retaining member) composed "oftwo parts for assembly pur-,

' poses and combining'in itself .bearing, ad-

justment and locking functions, and thus dispensing with a separate oradditional locking ring or analogous device such as has heretofore beennecessary in piston and rod connections of this general type, inaddition to an annularly continuous, or two-part lower bearing member.

The lower bearing or retaining member for the rod plate or hearingincludes in addition to its two main semi-annular members, means at oneside for registerin or retaining the two bearing members toget er, andmeans at'the other side for registermg and for spreading the members forlocking,

after adjustment; and the semi-annular.

members are also externally threaded to engage an internal thread 'inthepiston."

The characteristics and advantages of the invention are furthersufiiciently explained in connection with the following detaileddescription of the accompanying drawings, which show. representativeembodiments. After considering these examples, sln'lled persons willunderstand that many variations may be made without departing from theprinciples disclosed; and I contemplate the employment bf any structuresthat are properly within the scope of the appended claims.

Fig. 1 is a vertical section of a piston, rod ind bearing embodying theinvention in one orm.

Fig. 2 is a bottom plan of the lower or retaining bearing.

Fig.3'is a section at 33, Fig. 2.

Fig. 4 is a similar fragmentary section showing a slightly modifiedregistering or connecting device for the semi-an nular bearing members.

Fig. 5 is a similar section showing another modification.

' The invention is applicable to pistons of J I various types, but isespecially advantageous in'trunk pistons as used in internal" combustionengines, and is therefore here shown in conjunction with a trunk piston10, which may be of any known or suitable construction, except forfeatures related to the invention, as herein fully explained.

At any suitable axial position the cylindrical wall of the piston has aninternal shoulder 11 receiving the flange 12 of a substantiallysemi-spherical bearing, plate or member 13, which is convenientlyidentified as the up er piston hearing. The bearing plate is omoderately thick section and the lower face of the portion 13 provides asemi-spherical bearing surface 14.

The rod or pitman 15 has at its up er end a (usually integral)part-spherical caring plate 16, the upper, concave surface of which hasbearing contact with the surface 14. y The lower, concentric surface 17of the engaging with-the inner skirt surface as at 26, these recessesterminating in end walls 27, the end walls of the two segmentssubstantially abutting.

At one side, the segments are held in registered relation, or securedtogether, by suitable means such as a pin, or,.as shown, preferably insome cases by a screw 28. The screw passes through a bore in an end wall27 of one segment and engages in a threaded .hole 29 in thecorresponding wall of the other segment to retain the segments togetherat one side with sufiicient firmness to allow easy assembly andadjustment. When once assembled and located in the piston, the segmentsare held in proper position without entire or principal dependence uponthe screw or equivalent connecting device.

At the opposite side, the two abutting segment ends or end walls 27 aremutually taper-bored and threaded to receive a taper screw 30.

In assembling, the segments 19. and 20 are connected at one side as byscrew 28, and at the other side the tapered screw 30 is looselyinserted; the complete lower bearing is then inserted in the piston andits screwthread engaged with the skirt thread22, and the bearing isscrewed up to secure the desired bearing adjustment and is then lockedby tightening the tapered screw 30, (or equivalent means) by which thesegments are spread slightly and firmly located in the piston; andthereafter the bearing adjustment is secure and is maintained forpractically indefinite time, since wear and other difliculties attendanton pin and sleeve bearings are practically'eliminated.

n Figs. 1, 2 and 3, the registering or holding screw 28 is located in across-axial plane, and one of the lower-bearing segments such as 20 isprovided with a channel, or a hole 31 passing through its outer wall andinto recess 26, this hole being aligned with the screw holes in walls 27and large enough to admit the screw and screw head and also to admit ascrew driver by which the screw is tightened.

In Fig. 4, sucha hole or channel as 31 is dispensed with, and the axisof screw 28 and the screw holes is diagonal; that is, in a plane at adiagonal angle to the piston axis. One of the segment walls 27 isbevelled as at '32, forming a face at proper angle to receive the screwhead; the distance from ,this face 32 to the opposite wall surface 33 isslightly greater than the length of the screw, permitting easy insertionof the screw; and the screw angle is also such that a screw driver maybe easily applied to tighten it.

In Fig. 5, the screw arrangement or location is similar to that of- Fig.3 and no hole or aperture such as 31 is provided in the bearing segment20. In such cases, the screw may be of such length that it can beinserted into the screw holes; that is the screw is slightly shorterthan the distance between wall surfaces 34 and 35, and the screw may betightened by a'driver. having an angle-bit.

By the described construction or arrangement, the bearing and bearingconnections are reduced to probably maximum simplicity. Especially, nocontinuous or two-part retaining or locking ring is required in additionto the bearing segments 19, 20, as

in previous structures of this general type.

The lower bearing is made 1n two segments since it is not practicable tomake the central opening 25 large enough to pass over the sleeve bearingstructure at the lower end of the connecting rod, or over the bearingplate 16 at the upper end of the rod, when that plate is of properdiameter, and of circular form, to provide the desired ample bearingareas. There is therefore no necessity to reduce the diameter of the rodbearing plate 16, or to make it of non-circular or other irregularcontour, for assembly purposes.

It will be evident that in some cases the various bearing members may beinverted, in the sense that the upper piston bearing 13 may be turnedupward instead of down, makingits active bearing surface concave insteadof convex, and the other. bearing members will then be correspondinglyreformed or rearranged. This will bring the bearing as a whole to ahigher position inthe piston or nearer the head 10, which is desirableand practicable in some cases, especially if the piston-stroke is short.

The piston may have any desired ring groove arrangement, as at 40.Desirably, an annular oil-groove isfiprovided such as 41, locatedsomewhat above the periphery of the upper bearing 13, and one or morechannels 42 are cut angularly downward from the oil-groove to conductoil from the cylinder wall to the interior of the upper bearing plate,which has at its center an oil hole 43 by which oil is supplied to theengaging surfaces of the upper bearing and the rod bearing plate; andthis oil will work around the'periphery of the rod lates and lubricatethe engaging surfaces 0 that plate and of the lower bearing, regardlessof any splash oiling. Unusually ample and unefiective lubrication istherefore provided in a simple way, although the hearing will run almostindefinitely with negligible wear when provided with little or nolubricant, or much less than is necessary in a bearing of the pin type.

It is unnecessary to secure'the upper bearmg 13 in the piston exceptby'the retention afforded by the insertion, adjustment and locking ofthe lower bearing, as above de scribed. This upper hearing may be of ansuitable material and may be cast or forge or in some cases maybe ofpressed metal. The lower bearing segments may also be of any suitablemetal or alloy.

I claim:

1. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a part-sphericalbearingplate, and a lower piston bearing in segments forming an annulus havingperipheral threads engaging a thread in the piston and also having meansacting to expand the annulus and lock the lower bearing in'the piston.

2. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a part-spherical bearingplate, and a lower piston bearing in segments forming an annulus havingperipheral threads engaging a thread in the piston, and. also havingmeans actin to expand the annulus and lock the lower earing in thepiston, the lower bearing-having an upper part-spherical bearing surfacecooperating with the rod "bearing plate.

3. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a part-spherical bearingplate, an annular lower piston bearing having a part-spherical surfaceengaging the rod bearing plate and; composed of segments, meansretaining the segments in registry at one point, and at another point,means for spreading the segments to lock the lower bearing in thepiston.

4. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a part-spherical bearingplate, an annular lower piston bearing having a part-spherical surfaceengaging the rod bearing plate and composed of segments, means retainingthe segments in registry at one .point, and at another point, means forspreadingthe segments to lock the lower bearing in the piston, the lowerbearing having a peripheral thread engaging an internal piston thread.

5. A piston, 'rod and bearing structure comprisin a piston, an upperpart-spherical bearing t erein, a rod having a partspherical bearinglate, an annular lower piston bearing having a part-spherical. surfaceengaging the rod bearing plate and composed ofsegments, means retainingthe segments in registry at .one point, and at another point, means forspreading the segmentsto lock the lower bearing in the pis-in position.

ton, the lower bearing having a peripheral thread engaging an internalpiston thread,

and above the thread having a cylindrical portion to engage an innercylindrical piston surface.

6. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a part-spherical bearingplate, an annular lower piston bearing having a part-spherical surfaceengaging the rod bearing plate and composed of segments, the segmentsbeing connected at one side, and means at the other side of the segmentsfor relatively expanding them to lock the lower bearing in position.

7. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing there n, a rod having a part-spherical bearingplate, an annular lower piston bearing having a part-spherical surfaceengaging the rod bearing plate and composed of segments, the segmentsbeing connected at one side, and at the other side of the annulus atapered screw engaging a threaded tapered bore formed mutually in thesegments to spread them and lock the lowe bearing in position. I

8. A piston, rod and bearing structurecomprising a piston, an upperpart-spher- "ical bearingtherein, a rod having a part- 1 sphericalbearing plate, an annular lower piston bearing having a part-sphericalsurface engaging the rod bearing plate and composed of segments, a screwconnecting the segments at one side of the bearing annulus, and means atthe other side 0 the annulus for spreading the segments to lock thebearing in position;

9. A piston, rod and bearing structure comprising a piston, an u perpart-spherical bearing therein, a ro having a partspherical bearinglate, an annular lower piston bearing having a part-spherical sur- -faceengaging the rod bearing plate and composed of segments, a screwconnecting the segments at one side of the bearing annulus, one of thesegments having an aperture admitting insertion of the screw, and meansat the otherside of the annulus for spreading the segments to lock thebearing 7 in position.

ical bearing therein, a rod having a partspherical bearing late, anannular lower iston bearing having a part-spherical surace engaging therod bearing plate and composed of'segments, a screw connecting thesegments at one side of the bearing annulus, one of the segments havingan aperture admitting insertion of the screw and affording-access for atool to tighten it, and means 'at the other side of the annulus forspreading the segments to lock the bearing 11. A piston, rod and bearingstructure comprising a piston, an upper part-spherical bearing therein,a rod having a partspherical bearing plate, an annular lower pistonbearing having a. part-spherical surface engaging the rod bearing plateand composed of segments, a screw connecting the segments at one side ofthe bearing annulus, and at the other side of the annulus a taperedscrew engaging a 'threaded tapered bore formed mutually in the segmentsto spread them and lock the lower bearing in position.

12. A piston, rod and bearing structure comprising a piston, an upperpart-spherical bearing therein, a rod having a partspherical bearingplate, a lower piston hearing in segments combined to form an annulushaving peripheral threads engaging a thread in the piston, and meansacting to expand the bearing segments and lock the lower bearing in thepiston, the lower bearing having an upper part-spherical hearing surfacecooperating with the rod bearing plate.

HERMAN DOCK.

